Shell Oil Company — Pipeline Safety Interpretation

Page 1July 8, 1971 Mr. R. L. Brown Plant Manager Shell Oil Company One New Street Fall River, Massachusetts 02722 Dear Mr. Brown: An examination of information reported on the accident form filed in connection with the accident on January 29, 1971, in Waltham, Massachusetts, revealed two possible violations of the liquid pipeline safety regulations contained in Part 195. The first concerns the design pressure which was reported under Item M to be 2407(?) psig. 195.406 establishes the maximum allowable operating pressure for liquid pipelines. Section This section, which became effective on January 8, 1971, sets the limit on operating pressure for pipelines in existence on January 8, 1971, to be the lesser of two pressures: • The internal design pressure of the pipe determined in accordance with Section 195.106, or • The design pressure of any other component of the pipeline. Calculating the internal design pressure by the formula contained in Section 195.106, for 6-inch pipe with 0.250 inch wall thickness and made of Grade B material, gives an internal design pressure of 1902 psig based on a same joint factor of 1.00. The second concerns the patrol interval. The length of time between patrols on this pipeline was reported in Item J to be monthly. Section 195.412(a) requires each carrier to inspect the surface condition on or adjacent to each pipeline right-of-way at least every two weeks. Please provide this office with the explanation of this apparent noncompliance with the liquid pipeline safety regulations. Your prompt response to this request will be appreciated. Sincerely, Joseph C. Caldwell Acting Director Office of Pipeline Safety dal/195.106 71-07-08#